im working on a cannon that runs on hydrogen, but i have ran into a problem. the only pipe that could possible wistand a hydrogen blast safely is steel. what is the best way to put a spark gap in a steel chamber without it just shorting all the voltage through the pipe. my chamber is very small (3/4 by 3) so it needs to be small and simple. im thinking i should ground the pipe and just have the spark jump to the side of the pipe but im not sure.

basically im asking for the simplest and most effective way to put a spark gap in a metal chamber

make something that has both contacts attache to the wires and then just throw it in-
be carful with hydrogen
also dont inhale hydrogen thinking that it will have the same effects as hilium because it is five times lighter, not that i know that fom experience or anything-cough cause i dont-cough-cough

dont inhale hydrogen thinking that it will have the same effects as hilium because it is five times lighter, not that i know that fom experience or anything-cough cause i dont-cough-cough

that was wicked discrete

any way i was thinking if i sleeved a bolt in some small flexible plastic tubbing and some plastic washers and use that as a probe, then ground the pipe that would make it spark from the probe to the wall right?

If you used the sleeving approach you might have trouble keeping everything in place during combustion. You'd probably have more luck drilling a small hole through the center of a bolt and passing a length of HV wire though the hole then as you say, ground the chamber. Check out http://www.advancedspuds.com/nosparkplug.htm for a better description of what I'm talking about. You may want to use a longer bolt though so that the spark is closer to the center of the chamber.

turbohacker wrote:make something that has both contacts attache to the wires and then just throw it in-be carful with hydrogenalso dont inhale hydrogen thinking that it will have the same effects as hilium because it is five times lighter, not that i know that fom experience or anything-cough cause i dont-cough-cough

Inhaling hydrogen sounds so damn dangerous.
Imagine if you had a spark in your lungs!
Now taht probably will never happen, the results would be devastating!

does it have to be an electrical spark or could you use a lantern sparker or similar device. then you wouldn't have to bother with a grill ignitor, or as you were planning, an engine coil. or go with the spark plug idea. does epoxy conduct electricity? and is there some way to have a spark gap inside the cannon with two insulated wires going in? or have the chamber be grounded and have an insulated wire going into the cannon? or what if you cut a tiny hole and used a fuse? that would be awesome, like a real cannon.